Activities

The first stage of fixing up this old transmitter is disassembly. When Johnson built their gear they certainly didn’t spare the fasteners. This thing is held together by a ton of slotted head screws. Took forever to remove them all. Fortunately, the cabinet came apart really easy. The hardest part was removing the front

face. Once I had all the pieces separated I got busy with a bottle of Formula 409 cleaner and paper towels. This works pretty well on most stuff. I also used a tooth brush to really scrub the parts that had a course exterior finish. It didn’t work miracles, but for a transmitter nearing 70 yrs old it’s not too bad.

I now have access to the chassis of the beast. I’m impressed with the overall design, construction, layout, and quality. You can really tell these were built to last. The top side will definitely need some scrubbing, but I don’t see rust or corrosion. Of specific interest is the ganged, gear-driven variable inductor/capacitor tuning unit. Not only is it exceedingly grungy, but it’s not operating correctly. I believe this is the only item of concern up top.

The bottom of the chassis also looks as expected. A little dusty and some spider webs, but pretty clean. Fortunately, no surprises down there. I will have many electrolytic and waxy caps that will need replaced. Since I don’t own a leakage tester I’ll just have to assume they’re all suspect at this age. The worst thing is to let electronics just sit. Even very old components will continue to perform for decades if they’re just used regularly. I’ll also have to do some checks on the resistors as they’ve probably drifted, too. Some components are more critical than others depending on the particular circuit. This will just take some time to research the usual suspects and start ordering.

Fortunately, Johnson made a lot of these transmitters. I’d like to purchase a manual reprint but was able to easily find a PDF on the BAMA website. I’ve found them to be very helpful for everything except Heathkit (because of copyright licensing). I’ve had good luck purchasing reprints from Manualman and others.

Here’s a pic of this big honkin’ oil filled cap. No reason to include it except it’s cool. Just another example of the quality put into these rigs. Hoping to get the chassis all cleaned up and the roller inductor functional again. That will complete the first phase of the project. I think the next part will be more fun. I like working with components better than cleaning stuff up. Stay tuned.

Most hams who know me, know that I love to tinker and work on projects. Sometimes they even work out in the end. So begins this one. I’m an avid follower of the Soldersmoke podcast and website. Bill Meara N2CQR and Pete Juliano N6QW host a monthly podcast all about QRP and radio homebrew. Their inspiration has given me the courage to begin and successfully complete several projects. The Michigan Mighty Mite is a good example. One of their homebrew heroes is Ashhar Farhan VU2ESE who invented the BITX transceiver 14 years ago. Last year they reported that he’s selling the board fully constructed and tested. All you need to do is find a suitable enclosure and attach the peripherals. At the $45 price point it’s hard to beat as a development platform. The basic radio can be upgraded to stabilize the analog VFO or even improved by adding a DDS or PLL VFO quite easily. Low pass output filters can be added to take it from a 40m monobander to all band operation. I couldn’t resist!

With the circuit fully complete, this amounted to a one day project to get the basic assembly done. I found a suitable Christmas tin for a cabinet. The majority of my time was spent laying out and marking holes for the board standoffs and all the jacks and pots to be connected. It’s not exceedingly elegant but I was able to accomplish it all with a hand drill, pliars, and a couple wrenches. I chose the metal enclosure because I thought It might provide good shielding. Eventually I’ll probably add a small fan and punch some holes for ventilation. There should also be enough room to add an Arduino, DDS or PLL board, and cool LCD display. I think it would make a perfect radio for portable operation with a battery and 40m dipole at the park.

I wanted to include a couple shots of the innards. Everything came included with the kit, including the wiring pigtails to attach to the board headers. Pretty straight forward assembly. The HF Signals webpage has all the technical info, assembly

instructions, reference materials, and purchase info. The product is sourced and shipped out of India and constructed by a local women’s collective that helps provide skills and jobs. They typically arrive in less than a month. Not bad turn around time. Easy ordering with Paypal.

So here it is with a couple knobs out of the junk drawer. I trialed it on the bench and it plays great, minus the drift. Even that settles down after about 15 minutes. Crisp, clear analog audio…but you have to ride the AF gain what for having no AGC. I bet you could probably hack that into the circuit pretty easy, too. I could generally hear just about anything I could copy on the Flex-5000, so that says something about the sensitivity. This was a fun and functional one day project with only minimal soldering required. Looking forward to doing some more hacking on this one! Will try to produce a companion post with a little video production for everyone playing along at home. 73 all.

It appears as though I haven’t made a post in over a year. Time flies when you’re having fun…or extremely busy. It’s time to start a new project. In doing so, it might be fun to document the progress here in cyberspace (does anyone even still say that). It’s a good way to keep track of what’s been done, and also share with friends. Often times it might also be a topic of interest to many others outside your local chums. My posts on the ARD 230 project sure generated a lot of feedback from other owners. I received inquiries from hams as far as Spain and Germany! Strap in for the ride…here it begins.

I got energized to try something new after participation in the AM Rally early this spring. I’ve always been interested in vintage radio and the roots of our hobby. While CW holds the crown as oldest mode, AM isn’t too far behind. Many modern and vintage radios will operate AM, but I get a kick out of using vintage gear to operate a vintage mode. My lash-up for the event was a Heathkit DX-60A transmitter with the matching HG-10 VFO and Astatic D-104 mic. Classic 60’s and good for about 55W PEP. The receiver was a Yaesu FRdx-400. Early 70’s production, and it did pretty well for me, too. I didn’t yet have a dowkey relay so all the switching was done manually. Let me tell you, that’s a lot of work just to complete an exchange! My time was limited, and I made only one contact but I think the hook was set. Time to finally breath new life into this old gear that’s been sitting around cluttering up my shack.

Ten years ago I purchased a Johnson Viking II transmitter from a good friend and elmer Joel, K2LYC (now SK). I also came home with several other vintage pieces from his extensive collection, but that will become the subject matter of many future posts. The intent was to setup an AM station (Studio B) to accompany my then-modern Icom IC-756 station (Studio A). Somehow a decade passed away and, sadly, so did Joel. I guess I feel like I owe it to him to get this stuff playing again. So, it begins with the transmitter. I’m going to start there because usually they’re simpler. I’ve also had pretty good success fixing others. Fortunately, there’s loads of info available at my fingertips. This is the intro so I’m not going too deep. My plan is to remove the chassis from the cabinet for overall cleaning and inspection. I’ll replace any faulty components and perform only the mods that are proven and considered best practice. No total restoration needed. I’m sure every scratch and scrape tells a story. It’ll never be a mint specimen, just an honest workhorse. Eventually it’ll pair with my Collins 75A-3 (which will probably be the next project). But you see I’m already ahead of myself. Next post will start getting into the real heart of the job. 73!

The cold winter months are good for spending time in the radio shack, and also in a comfy chair doing a bit of reading. I just finished reading this book and thought I’d write up a little review to share with my blog followers.

Minimum QRP is written by Peter Parker VK3YE. Many followers of Soldersmoke and youtube will recognize Peter from his many videos on low power operation, pedestrian mobile, and homebrew electronics. In his book, Peter covers all aspects of low power operation from radio, to antenna, to operating location, and even strategies for successful operation and maximizing the chances of making contacts. He covers HF/VHF/UHF, both terrestrial and satellite. It’s impossible to cover everything QRP in great deal, but this book offers a lot of great info on the subject.

I don’t really consider myself a QRP aficionado but I found the book quite enjoyable. It’s easy to read and not overly technical in any way. If nothing else, it offers a great deal of encouragement and support to people interested in pursuing low power operation. At $5 via Amazon Kindle it’s hard to argue with the price. I’ve certainly wasted more money on useless items!

Most of my ham friends know I’ve been a devoted listener of the SolderSmoke podcast for some time. Bill Meara N2CQR and Pete Juliano N6QW make a great team discussing the building and operating of all manner of homebrew, boatanchor, and QRP gear. Their enthusiasm is obvious and they really give the listener a sense of confidence that it just might be possible to really build something yourself in this modern age.

Building components and constructing circuits is to me the essence of ham radio. I’ve built small kits like the N0XAS Pico Keyer from Ham Gadgets and similar odds and ends, but never any “real” ham gear. I’m kinda like the average Joe that watches the home remodeling show on TV and thinks it’s cool to restore the 100 year old house, but lives in a newer house with little maintenance. It all sounds glorious, but you have no idea where to start.

Enter the Michigan Mighty Mite. This simple transmitter requires only seven components and produces around 500 mW RF output. To up the ante Bill sent out the necessary 3.579 MHz colorburst crystal for free to anyone who emailed him a request and promised to use it. Pete built the circuit and added some pro tips of his own on MMM construction on the blog. Now this seemed to be a project I could handle! I fired off an email in short order.

My crystal got torqued by the USPS!

What arrived was something of a disappointment. Evidently USPS sorts mail with a steam roller. My precious crystal looked like momma worked it over with a rolling pin! This depressed me enough that I delayed building the transmitter for some time. I panicked and purchased a whole bag of crystals, just to be safe. Eventually I turned up some magnet wire, a pill bottle and the necessary capacitor and resistors. The remaining air variable cap was ordered from Amazon. Turns out they have all manor of useful materials, who knew?

First winding with tap.

The hardest part was winding the coil. That wasn’t too bad, though. I held it together with tape. Everything was assembled on a bread board for trial. I must admit to being overjoyed when I saw the visual waveform on the PowerSDR panafall display of my Flex-5000A main shack radio. So much so, that I ran through the house calling for my YL, KC9TAH. She was in the shower

Second winding over the first goes to antenna and ground.

and thought I’d cut off a finger or something while in the mad scientist lair. Much to her dismay, it was only a nasty CW signal emanating from the Flex speaker. She did humor me by going out to see the marvelous project before asking me what I was going to fix for lunch.

So where do I go from here? I have a small piece of perfboard on the bench. I guess I should assemble it on that in a proper arrangement. My friend Brian KB9BVN has requested a QSO but I’ll need to build a low pass filter to knock down the harmonics. No sense of incurring the wrath of the FCC and homebrewers everywhere. My next project is a small regen receiver and the Ugly Weekender and Ugly Weekender II combo. Both of these come from old issue of QST. I have the circuit boards from Far Circuits and plan to build them with the boys. Might as well infect the next generation with a case of “the knack” if at all possible.

Well, the HV power supply seems to be humming along nicely. The meter on the control head displays 2500 VDC which is probably about right considering my line voltage in the shack (248 VAC). As promised, I measured all the resistors that were removed from the supply and noted their values. I also noted their specified range based on the five percent tolerance value. As expected, not a one was in spec. I’m not sure that this really makes much difference as the power supply isn’t exactly a calibrated circuit, but it would be silly not to replace them while refurbing the supply. They’re inexpensive and easy to replace. I substituted metal film resistors of the same value and power rating rather than the original carbon composition.

I haven’t had a single issue at all with breakers tripping on the amp or sub panel since making the repairs. I’ll conclude that it was definitely a faulty filter cap (or maybe several). It uses six 240 uF 450V computer grade electrolytics in series for a total of 40 uF DC filtering goodness. I don’t have a way to test them at this time to determine their values. Actually, I don’t even have them anymore. The neighbor kid (Jacob KC9ZYV) wanted them (and also the caps from the Amp Supply LK-500 NT power supply I refurbed last year). He mentioned something about a rail gun…future mad scientist at work!

I recorded the values for everyone on a pad of genuine Purdue green engineering graph paper. I still have nearly a full pad of this stuff after nearly 20 years. I wasn’t an engineering student! I hope you all find the info interesting. The next order of business for the amp is to synch the DC drive system with the Tune and Load air variable caps in the RF deck. Then I can calibrate them all for roughly every 100 KHz of each band and let the amp auto tune itself!

I got an enjoyable surprise in my email last weekend. Gerald PA3GEG from the Netherlands sent me an mp3 file of our recent DX contact. Conditions have been pretty favorable for 10 and 12m lately and I’ve been trying to take advantage. I actually worked Gerald about a week before on 12m USB. It was neat to hear my own audio from so far away. I’ve since added a couple TX profiles for my Flex-5000 (one for DX and another for rag chew) so hopefully I’ll sound even better now. He sent me a couple links so I went ahead and signed his guest book and checked out his page on QRZ.com. There’s some good stuff there worth taking a look. You can see his page here. It was an enjoyable contact for both of us. Thanks Gerald!

It’s been a long and busy summer and my blog has suffered. I’ve neglected amateur radio quite a bit due to a heavy work schedule. With the onset of Indiana winter and the first snow on the ground I may be able to carve out a little more shack time now. I’ll try to do a quick recap of the last five month and hit any ham radio highlights.

We were sorely in need of some better antennas and feedline at the WD9BSA shack. We were able to trade off some excess equipment for a 500 foot spool of LMR-400 feedline. This allowed us to make brand new runs out to the antennas. We now have two multi-band antennas in the air and ready to go whenever the Scout radio station is activated and on the air.

Unfortunately, I missed Field Day this year because of work. I was able to operated portable Field Day style at Ransburg Scout Reservation. After a more than twenty year absence from Boy Scout camp, I returned with my oldest son, Jared, for a week in July. I had a portable station setup in the STEM area and managed several contacts. The station included a Buddipole antenna and an older Kenwood TS-450SAT with matching power supply. Some contacts of interest were: W100AW ARRL Centennial station, W9ZL special event station at EAA Airventure, and DX station CO6LC in Cuba. Our troop’s Senior Patrol Leader earned his ham license so we were able to communicate throughout camp with HT’s.

I have numerous old boatanchor radios in the shop. They’re in various stages of disrepair, unfortunately. I was, however, able to get two of them fired up using a variac. The two I’ve been working on are a Hallicrafters S-53A and Hammarlund HQ 100A. They both exhibit some audio hum and could use some refurbishing, but so far they receive pretty well on a wire antenna. The S-53A now rests on the mantle in my family room and is occasionally fired up for a little AM listening enjoyment.

My most recent project is getting the shack cleaned up for winter operation. I’ve moved around a bunch of gear to improve the overall layout. Some items have been packed away for a later date and new projects are on the bench. I built a new shack computer to operate the Flex-5000 and all the software that goes along with modern radio operation. In the last couple days it’s been getting a workout on 10m due to some decent propagation to Europe. I have more ham blog goodness on the way…but that’s a teaser to keep you coming back. 73 for now.

April 19 I was able to attend my second high altitude balloon chase event. As part of a nationwide competition the Purdue AMET club launched two balloons. The Purdue Physics Society also launched a balloon. This required a concerted effort to chase three balloons launched at different times from two different locations. I was able to get in on the balloon projects since I’m a member of the Purdue Amateur Radio Club. We’ve partnered with the other clubs to assist in tracking and comms support. In the process, we’ve been able to encourage many of the club member to get licensed. We even started our own PARC VE team.

In addition to the various club members out tracking I also had my son, Jared, riding shotgun; and friends Nick N9SJA and Tabb W9TTW in their mobiles. We were able to track and recover two of three balloons. AMET balloon #2 is MIA and hopefully will be recovered by someone and returned to the club. AMET balloon #1 was a special zero pressure balloon that was actually totally constructed by the club members. It’s designed for an experimental payload. What it lacked in speed and altitude it made up for in endurance. We followed it all the way to the end of a dirt road outside a small town in rural southern Ohio. We were actually able to see the balloon and follow it as it floated along at 40,000 feet altitude. I wouldn’t have believed that possible. The Physics balloon ended up in a tree in a golf course community in Fishers, Indiana.

Liftoff for the zero pressure balloon.

It was nice to really make use of the APRS features of the Kenwood TM-D710 in my mobile. We were able to copy the balloon’s beacons direct from our mobiles. It was also helpful to be able to tether my tablet to my cell phone and view the balloon in real time on maps. This also helped us plot our route as we followed along. At one point the balloon went right over my house and used my digipeater. That was really neat for me. It definitely took us into some unfamiliar territory. We knew it was a good sign as it went past Dayton, OH. Being that near to Hamvention land was some good mojo. Can’t wait to get back there in a few weeks.

I’ve included a pic that shows the flight path of AMET #1. You can see the red line is the path it traveled. The blue line is from the pickup point back home to West Lafayette. They must have turned off the beacon and then turned it back on again later. It was neat to follow it along and see it hanging in the sky, especially after it got below 10,000 feet. As it got cool in the evening the altitude really started to drop. I wish I could’ve gotten a picture of it lit up by the sun and floating along about 5000 feet thorugh some rolling fields out in the country.

We’re looking forward to some more balloon projects this summer as many of the members will be sticking around campus. We also have plans for using the kite antenna again. Maybe this time we can send up a small, low power repeater.

For a long time I thought that APRS was pretty much a solution to a nonexistent problem. It provides position tracking, but how many times can you follow your buddies around on a map before that gets boring? It uses a 1200 baud packet radio protocol, but most packet has been dead for years. The only exceptions are a few DX cluster nodes and some emcomm stuff. And even at that, 1200 baud is slow when most any gear can run 9600 now. So, what’s the attraction?

My thoughts changed after tracking a high altitude balloon. APRS really proved itself invaluable in this endeavor. We were able to not only copy direct packets from the balloon, but also see the beacon packets on aprs.fi using a smart phone when we were out of range. This made recovering the payload much easier–of critical importance when there’s the potential for a high altitude to travel outside of state lines and beyond.

At some point the location beacons stop getting reported to the APRS-IS network if it gets out of range of a digipeater. The last two times it was when the balloon was still 2-3000 feet up. This prompted me to examine how many digipeaters were in my local area. I live directly between two fairly large cities. Indianapolis and Lafayette both have wide area digipeaters but there aren’t any local digi’s in my area. Just one I-gate in Lebanon. I thought it might be nice to set one up. This should help provide coverage for local passing motorists and may be of help to the local ARES team in the future. Just last fall we had a destructive tornado come through my county only 10 miles away!

I’ve done a lot of reading on different ways to setup digi’s and I decided to purchase an older Kenwood TM-D700. This dual band data radio will operate APRS on one VFO and also VHF or UHF FM phone on the other VFO simultaneously. This is different than many dual banders that will operate phone on both bands, but not data and phone at the same time. The added benefit is that I now have a handy radio in the house for repeater/simplex operation. It was easy to setup the APRS features and get the packets beaconing. Then I enabled it to digipeat local WIDE1-1 packets and saved this config to one of the Programmable Memories. Phase two involved taking the digi to the next level. I downloaded

The guts of the system are housed in this box under the table.

aprsisce/32 on my spare laptop. I had to make a couple changes to the xml file and then it would operate as a digi. Then I changed the 700 to run as a KISS TNC and connected it to the laptop. This proved simple once I found correct straight through F/F serial cable. The 700 still has an old school DB9 male serial port so I didn’t have to construct a special serial cable with a mini DIN connector like the newer TM-D710 requires. After making all these changes I saved the config to another Programmable Memory channel. Now my digi can operate stand alone or with the laptop. Using the laptop is nice since it shows all the activity in the area and also handles APRS messaging.